Part of the family obviously. Dogs have been shown to do incredible things, and to help humans in incredible ways. A dog is born into this world with an instinct to please its owner, and dogs are extremely loyal. They are amazing and should be treated with love and care just like any human.
Think about it, there are dogs who have detected cancer in their owners, service dogs who help tremendously with people in need of them, dogs who will protect and die for their owners, dogs are capable of doing so many things it's silly to think they are just amusement for children.
Dogs are mans best friend for a reason. They aren't just some walking, breathing, emotionless life source with no meaning which seems to be what some people think.